111609 has 6 divisors (see below), whose sum is σ = 161226. Its totient is φ = 74400.

The previous prime is 111599. The next prime is 111611. The reversal of 111609 is 906111.

It can be written as a sum of positive squares in only one way, i.e., 90000 + 21609 = 300^2 + 147^2 .

It is not a de Polignac number, because 111609 - 2⁴ = 111593 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 111591 and 111600.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 111609.

It is not an unprimeable number, because it can be changed into a prime (111659) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6192 + ... + 6209.

It is an arithmetic number, because the mean of its divisors is an integer number (26871).

2¹¹¹⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

111609 is a deficient number, since it is larger than the sum of its proper divisors (49617).

111609 is a wasteful number, since it uses less digits than its factorization.

111609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12407 (or 12404 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 18.

The square root of 111609 is about 334.0793318959. The cubic root of 111609 is about 48.1466866895.

The spelling of 111609 in words is "one hundred eleven thousand, six hundred nine".